Make debug target enable assertions properly.
Make debug target enable assertions properly.

Cut & paste error from opusfile's Makefile.am.

nvoron23/daala,luctrudeau/daala,nvoron23/daala,jmvalin/daala,KyleSiefring/daala,smarter/daala,vr000m/daala,jmvalin/daala,luctrudeau/daala,smarter/daala,xiph/daala,xiphmont/daala,felipebetancur/daala,iankronquist/daala,KyleSiefring/daala,ascent12/daala,ascent12/daala,kodabb/daala,xiphmont/daala,xiph/daala,xiph/daala,ascent12/daala,felipebetancur/daala,iankronquist/daala,kustom666/daala,kbara/daala,felipebetancur/daala,kustom666/daala,tdaede/daala_awcy_runs,kustom666/daala,mbebenita/daala,mbebenita/daala,smarter/daala,xiphmont/daala,tdaede/daala,tribouille/daala,luctrudeau/daala,KyleSiefring/daala,KyleSiefring/daala,tdaede/daala_awcy_runs,HeadhunterXamd/daala,kodabb/daala,tribouille/daala,kbara/daala,ycho/daala,xiph/daala,tribouille/daala,iankronquist/daala,tdaede/daala,luctrudeau/daala,jmvalin/daala,HeadhunterXamd/daala,xiph/daala,nvoron23/daala,ycho/daala,kbara/daala,vr000m/daala,KyleSiefring/daala,ycho/daala,kodabb/daala,ascent12/daala,tribouille/daala,felipebetancur/daala,luctrudeau/daala,jmvalin/daala,iankronquist/daala,tdaede/daala,HeadhunterXamd/daala,kbara/daala,ycho/daala,mbebenita/daala,smarter/daala,kustom666/daala,tribouille/daala,kodabb/daala,xiphmont/daala,HeadhunterXamd/daala,iankronquist/daala,ycho/daala,xiphmont/daala,tdaede/daala_awcy_runs,jmvalin/daala,tdaede/daala_awcy_runs,nvoron23/daala,kustom666/daala,nvoron23/daala,vr000m/daala,ascent12/daala,tdaede/daala,kodabb/daala,vr000m/daala,vr000m/daala,mbebenita/daala,mbebenita/daala,felipebetancur/daala,HeadhunterXamd/daala